RT Journal Article
T1 Chromosome Nondisjunction and Instabilities in Tapetal Cells Are Affected by B Chromosomes in Maize
A1 Chiavarino, Mauricio
A1 Rosato, Carmen Luisa Marcela
A1 Manzanero, Silvia
A1 Jiménez Díaz, Guillermo
A1 González Sánchez, Mónica
A1 Puertas, María
AB Abnormal mitosis occurs in maize tapetum, producing binucleate cells that later disintegrate, following a pattern of programmed cell death. FISH allowed us to observe chromosome nondisjunction and micronucleus formation in binucleate cells, using DNA probes specific to B chromosomes (B's), knobbed chromosomes, and the chromosome 6 (NOR) of maize. All chromosome types seem to be involved in micronucleus formation, but the B's form more micronuclei than do knobbed chromosomes and knobbed chromosomes form more than do chromosomes without knobs. Micronuclei were more frequent in 1B plants and in a genotype selected for low B transmission rate. Nondisjunction was observed in all types of FISH-labeled chromosomes. In addition, unlabeled bridges and delayed chromatids were observed in the last telophase before binucleate cell formation, suggesting that nondisjunction might occur in all chromosomes of the maize complement. B nondisjunction is known to occur in the second pollen mitosis and in the endosperm, but it was not previously reported in other tissues. This is also a new report of nondisjunction of chromosomes of the normal set (A's) in tapetal cells. Our results support the conclusion that nondisjunction and micronucleus formation are regular events in the process of the tapetal cell death program, but B's strongly increase A chromosome instability.
PB Oxford University Press
SN 1943-2631
YR 2000
FD 2000
LK https://hdl.handle.net/20.500.14352/95341
UL https://hdl.handle.net/20.500.14352/95341
LA eng
NO Chiavarino, A. M., Rosato, C. L. M., Manzanero, S. et al. «Chromosome Nondisjunction and Instabilities in Tapetal Cells Are Affected by B Chromosomes in Maize». Genetics, vol. 155, n.o 2, junio de 2000, pp. 889-97. https://doi.org/10.1093/genetics/155.2.889.
NO This work was supported by grant PB 98-0678 of the DGICYT of Spain.
NO Ministerio de Educación y Ciencia (España)
DS Docta Complutense
RD 6 abr 2025